bro im in the same boat as you. but i have this all year. im a mover. i carry heavy shit and run up and down stairs all day. never lost a gram of muscle. just bring enough food. they thought i was crazy when i showed up with a full size cooler the first day. do what you gota do.

I know where you're coming from... I've done labor for years. When I'm workin and sweatin real hard, food doesn't sound good, and when I eat I feel sick to my stomach. But I am tryin to eat anyway. I pack a lunch of 1 dozen hardboiled eggs peeled, 1 8oz greek yogurt, granola bar, protein bar, either fish or chick n veggies(i often eat it cold) 2 cups of oats w/ cinnamon n raisins cooked, and a natty pb&j w/ natural jelly, or banana slices on whole wheat. 4 .5liter bottles of water... It's kind of a pain in the ass packin it and carrying it. Just depends how bad you want it I guess? This is my first summer trying to maintain/gain weight. It's hard when some days it feels like a sauna. All years in the past I would always jus not eat (when it was real hot) at work or if I did It was small and light. This year? Somedays are easier to get the food in than others. All you can do is try bro, or u still have goth's plan for a back up? Lol

High cal weight gain shakes..

I find the best thing to do is pack food you can have within a few minutes and doesn't require too much cleanup and dishes. Yogurt and quick oats,nuts, milk, whey protein, a bottle of olive oil. I have a water cooler at work but so I just bring a bottle of olive oil and mix the protein with water in a styrofoam cup. Never have to leave the office and you have a meal in 2 mins!

I do manual labor In Summer usually too, some guys actually make good gains this way cause depending on the labor it's like an active rest. Just take in extra calories get an extra hour rest at night or a good nap and keep the workouts short but intense. I remember Arnold and Franco ran a brick laying business for a time in the early days.. If they can lay brick in California heat all day and win olympia titles, no reason us mortals can't make decent gains.

I know bodybuilders who have bought scooters and segways just so they can ride almost anywhere instead of walk, as walking would burn valuable calories. If they could actually ride them laying down they would.
The solution here is to quit your job.
I know that sounds radical, but you can make more money by stealing or robbing. And if you use an automatic weapon, you only have to pull the trigger once, thereby saving calories. Besides, when you're in the middle of robbing a convenience store, nobody's going to say shit if you walk over to the cooler and grab a Muscle Milk while the girl is filling the sack with cash. Gotta keep that protein flowing.
Another alternative is to marry a rich grrrl like I did. Sure, her parents may not approve of your "job" (working out, eating, and sleeping), but you'll be so huge, her daddy won't have the guts to actually say it to your face.
Also, make sure you've invested in modern technology....like remotes for all the doors in your home and autos, electric toothbrush and razor, a shock-collar for your dog so he can walk himself......and either the latest sex-gadgets for your wife or a newly-released inmate-----there's no sense in sacrificing a 2 hour workout just for 17 seconds of pleasure.
If all else fails, consider the use of synthol. That shit tends to stick around for a while, and even though you may look like a dumbass, you won't look as dumb as a high school basketball player standing in line to pay $50 for a jug of weight gain.

Forums in food.....title was To Shake. It's a writeup on making your own high protein jerky at home. Good read..

You might consider packing full fat Greek yogurt to work with you. That shit is delicious, packed with calories, fat, and most importanly double the protein of regular yogurt. Sure, buying something with the name "Greek" is as embarassing as purchasing tampons for your wife, but it's worth it.
Also, pack nuts with you. Literally and figuratively. They are a great source that you can keep in your pocket and eat all day long.